PELLEGRINISAURUS POWELLINOV. GEN. ET SP. (SAUROPODA, TITANOSAURIDAE) FROM THE UPPER CRETACEOUS OF LAGO PELLEGRINI, NORTHWESTERN PATAGONIA, ARGENTINA

Abstract

The holotype of Pellegrinisaurus powelli nov. gen. et sp., recovered from levels of AlIen Formation at lago Pellegrini (Province of Río Negro, Argentina) is described. Previous reference of this specimen to c. Epachthosaurus sp. is discarded, as it does not share derived features with the holotype of Epachthosaurus sciuttoi Powell. Probable autapomorphies of Pellegrinisaurus powelli are: (1) transverse width of the centrum of the posterior dorsal vertebrae approximately twice the maximum dorsoventral depth, and (2) mid-posterior and posterior caudal vertebrae with anteroposteriorly elongated and dorsoventrally depressed neural spines, the anterior ends of which are higher anteriorly than posteriorly. Pellegrinisaurus powelli is considered a probable sister taxon of the Saltasaurinae on account of low vertebral centra in the medial and posterior caudals, with dorso-ventrally convex lateral faces.